From help-octave-request at bevo dot che dot wisc dot edu Mon Jan 26 11:00:55 2004 Subject: Re: Understanding how octave works... From: Ross Vandegrift To: Joerg Frochte Cc: help-octave at bevo dot che dot wisc dot edu Date: Mon, 26 Jan 2004 11:59:45 -0500 On Mon, Jan 26, 2004 at 03:14:15PM +0100, Joerg Frochte wrote: > This has something to do with the fact that A is very close to be singular. > > octave:21> cond(A) > ans = 2.9251e+18 If you're interested in algorithms that are capable of dealing with problematic matricies, check out a text on numerical analysis from your local library. In the course I took last semester, we used Burden and Faires, "Numerical Analysis". This text is pretty broad about numerical algorithms in general and covers everything from linear systems to differential equations. It includes lots of discussion of ill-conditioning. There's also a text that came up a lot by Van Loan, but I don't recall the title. I'm sure someone else can point you in this direction - it covered more of the advanced numerical approaches for problematic systems and iterative methods. -- Ross Vandegrift ross at willow dot seitz dot com A Pope has a Water Cannon. It is a Water Cannon. He fires Holy-Water from it. It is a Holy-Water Cannon. He Blesses it. It is a Holy Holy-Water Cannon. He Blesses the Hell out of it. It is a Wholly Holy Holy-Water Cannon. He has it pierced. It is a Holey Wholly Holy Holy-Water Cannon. He makes it official. It is a Canon Holey Wholly Holy Holy-Water Cannon. Batman and Robin arrive. He shoots them. ------------------------------------------------------------- Octave is freely available under the terms of the GNU GPL. Octave's home on the web: http://www.octave.org How to fund new projects: http://www.octave.org/funding.html Subscription information: http://www.octave.org/archive.html -------------------------------------------------------------